Automatic chuck



Jan. 2.6, 1960 R. P. GARRISN EIAL 2,922,657

AUTOMATIC CHUCK 2 Sheets-Sheet 1 Filed March 3, 1958 5 R u gli ull www mm1 e Thil wmp/WWW Y f @Gown m R0. m m 5 w Jan. 26, 1960 Filed March s,1958 R. P. GARRISON ET AL AUTOMATIC CHUCK 2 Sheets-Sheet 2 Bymwmm UnitedStates Patent AUTOMATIC CHUCK V Ralph P. Garrison, James 0. Garrison,and 'David D. Walker, Dayton, Ohio, assignors to Garrison Machine Works,Inc., Dayton, Ohio, a corporation of h10 Application March '3, 1958,Serial No. 718,819

17 Claims. (Cl. 279-106) This invention relates to chucks and moreparticularly to a novel bore edge chuck. h

With the development of automation many chuckmg devices have proveninadequate to serve their intended function. Moreover, withtechnological advancement, the shapes and nature of parts which must bechucked and machined have become more diversified. Accordingly, a demandand necessity has presented itself for lmore versatile chucks capable ofproperly functioning,

successively and automatically, so as to enable precision machining ofparts with a minimum of induced stress and strain.

The present invention fills a need in this area. I t providessubstantial improvement in chucks which sim'phfies them and renders themhighly effective for continuously automatic chucking operations.Practical ern-bodiments of the invention in preferred formenable thechuckvWork may be precision machined as to its peripheral contour, freeof any holding distortion. The work pieces which may be handledappropriately by the invention embodiment need only have a singlemachined face and the internally bored parts need not have a uniformcross-sectional contour. While a particular application and structure ofthe invention will be described herein to highlight the versatility andefficiency thereof in use,

those versed in the art will clearly recognize that thel application andembodiment of the invention is not so limited, nor is such intended.

A primary object of the invention is to provide irnprovements ininternal chucks whereby such devices may 2,922,657 Patented Jan. 26,1960 fice larities of its chucking surface and its cross-sectionalcontour.

Another object of the invention is to provideY a chuck -havingsimplified and improved automaticallyy operating work retention means.

Another object of the invention is to provide draw bar operated chuckswith simplified and improved latch means. v

Afurther object of the invention is to provide a novel bore edge chuck.

A further object of the invention is to provide a diaphragm control in abore edge chuck.

A further object of the invention is to provide an automatic chuckpossessing the advantageous structural features, the inherentmeritorious characteristics and the mode of operation herein mentioned.

With the above and other incidental objects in view as will more fullyappear in the specification, theV invention intended to be protected byLetters Patent consists of the features of construction, the parts andcombinations thereof, and the mode of operation as hereinafter describedor illustrated in the accompanying drawings, or their equivalents. v j

Referring to the accompanying drawing vwherein is shown one butobviously not necessarily the only form of embodiment of the invention,

Fig. l is a longitudinal cross-sectional View of a chuck in accordancewith the invention with a work piece chucked thereto;

Fig. 2 is an end view of the device of Fig. l showing the work piece ina chucked condition; and

Fig. 3 is a longitudinal cross-sectional view similar to that of Fig. lbut showing the parts in a work ejecting condition.

Like parts are indicated by similar characters of reference throughoutthe several views.v As shown, a chuck housing 1 is provided having athrough bore which is expanded in stepped fashion from its inner face 2to its outer face 3. At the face Z of the housing 1, the bore is definedby a coaxial tubular projection 4 integral with the housing andprojecting rearwardly therefrom.

The tubular projection 4 provides a bearing for a cylindrical rod 5which is connected to a draJw bar (not shown). Therod 5 extends throughthe housing and is reciproc-able relative thereto.

Immediately forward of the tubular projection 4 within the housing 1,the through bore is uniformly expanded be more economicallymanufactured, adaptable to a wider variety of applications, moreefiicient andv satisfactory in use, have a longer effective operatinglife and require a minimum of maintenance.

A further object of the invention is to provide an im-` at anintermediate section 6 to a plane parallel to and spaced inwardly fromthe outer face ofthe housing 1 where it is further expanded to provide a-shoulder 7 parallel to-the outer face 3. From the shoulder 7, the boreof housing 1 is conically expanded to its outer face. A screw 8 isradially engaged through the wall of the tubular projection 4 to haveits inner stud extremity 9 project within an elongated substantiallyrectangular n otch 10 in the surface of the rod 5. This preventsrotative movement of the rod relative the housing.

A plate 11 having a central conically formed projection .12 seats overthe outer face of the housing 1 to dispose its conical projection 12 innested relation to the conically expanded surface of the bore ofhousing 1. 'Ihe plate 11 and its integral projection 12 are centrallyapertured coaxially with the through bore of the housing 1.- Theoutermost face of the plate 11 is concentrically recessed in steppedfashion inwardly to its -central aperture. The first stepprovides anarrow annular shoulder 15 parallel to its outer faceand immediatelyinward of its periphery. A resilientme'tallic diaphragm 16, which iscentrally apertu'red, v'peripherally seats t the shoulder 15. The'diaphragm 16 is provided with an integral tapered projection 17 aboutand defining its central aperture. A second step in the outer face ofthe platen 11 provides an intermediate annular shoulder 18 and a furtherstep inwar-dly to the central `aperture of .the plate 11 provides a-relatively narrow annular shoulder 19 coaxial with the aperture in thediaphragm.

A generally tubular guide element 20'seats at its inner extremity to theshoulder 19, coaxially with the bore of the housing 1. The guide 2l)projects through the central aperture in the diaphragm and isperipherally enlarged at 21 Vimmediately forward of the taperedprojection of the diaphragm while its outer extremity is externallytapered at 22. The internal diameter of the guide 20 is reduced at itsinnermost end to provide a cylindrical bearing surface for theprojecting end of the rod `5. The

guide 20 is fixed lto the plate 11 by screws 23 engaged through theprojection 12 and'into thebase thereof.

Screws 24 engage through the shoulder 18 of the plate 11 into thehousing Aface 3 to fix the plate thereto. The diaphragm 16 has`apertures 25 aligned with the heads of 'the screws 2d which projectfrom the shoulder 18.

Rest buttons 26 are circularly arranged on the shoulder 18 of the plate11 and threadedly engaged thereto. The rest buttons projectperpendicularly from the shoulder and through aligned apertures 27 inthe diaphragm immediately about the tapered projection 17. An annularring plate 29 fixed over the outer edge of the outer face of the plate11 by screws 31 has its inner periphery overlying the periphery of thediaphragm 16 to fix'it to the shoulder 15. Y p

A lrod extension element 32 is xed in a central recess in theforward-extremity of 'the rod 5 to project coaxially within the guide20. The diameter ofthe extension 32 is less than thatof the rod 5.

A sleeve 33 is 'slidably mounted on'the extension 32, forwardly oftheinterna'lly reduced portion of guide 20 which provides a shoulder 34facing outwardly relative the chuck body.

The endof sleeve 33 adjacent the shoulder 34 hasv circularly spacedrecessesfseatingsprings 39. The springs 39 project from the sleeve 33about V:guide pins 69 fixed Ato `shoulder 34 to bias the sleeve from theshoulder. The forward end of sleeve 33 has three equidistantly spacednotches, each transversely bridged by a pivot pin 56. Each pivot pin 56pivotally mounts vthe y'inner end of a iinger35. The lingers 35 extendaxially of guide 20 about the rod extension 32 whichhas an expandedvextremity in the form of a disc 38 having a rounded periphery. Thefingers 35 are identical in v.that they have outwardly projecting hookextremities 36 which are triangular in cross-section and voutwardlyoffset .about the disc 38. The 'nature -of the offset is that theinnermost surfaces vvof the fingers 35 initially ydivenge at their hookportions 36to provide sloped cam surfaces 58 and then extend axiallyagain about Vthe `disc 38. The guide 2l) has circularly extended slots37 adapted to align with lthe hook Jextremities of the lingers 35.` Theforward edges of the slots 37 aretapered inwardly and Aforwardly of theguide 2t) generally parallel to the outermost Vsurfaces of therelatively adjacent hook portions of the elements 35. As may be seen inFig. l of the drawings, drawing rod 5 and extension 32 rearwardlyrelative the body 1 results in the disc 38 engaging the cam surfaces 5Son the inner sides of lingers 35. This causes an axial displacement ofngers 35 and sleeve 33 compressing springs 3% between the sleeveand-shoulder 34. Also, the hook extremities of the lingers 35 are'aligned with slots 37 and cammed outwardly thereofunder the influenceof disc 3S. Forward movement of disc 38 relieves the springs 39 which-give an `axial .forward thrust'to the sleeve to .initiate the cammingofthe hook extremities Aof fingers 35 within vguide 20.

`Within lthe intermediate .expanded section 6 of the housing bore,immediately forward 'lofithe rear v.face 2, a shedder rplate 43.isslidablymounted'about and onirod i5.

The shedder plate includes a tubular hub 44 with an annular skirt 45.Pivoted in the housingv 1 adjacent the rear of the shedder 43 is .aright angled latch 40 including a depending arm 46 disposed in anelongated rectangular notch 41 in the surface of the rod 5 and aforwardly projecting arm provided with a hook extension 47 for engagingin a notch 48 in the hub of the shedder 43. The housinglhas a radialaperture aligned with the latch hook 47 accommodating a 'spring biasedstud 42. A screw 49 contains the stud 42 in biasedrelation -to thelatch. With the rod 5 in forward position, `as ,shown in Fig. 3, thelatch arm y46 is cammed counterclockwise by rod 5 yto bias-the Astud .42into its guide aperture and provide the shedder 43 with freedom to moveforwardly relative to rod .5 under :the influence of springs 50 seatedto the rear thereof in axial recesses in the housing and tubularprojection 4, parallel to rod 5.

Guide studs 52 project rearwardly from the shedder 43 within the springs50. Shedder pins 54 are circularly spaced in the skirt of the shedder 43to project forwardly vthrough aligned Aapertures in the plate 11 anddiaphragm 16 in the path of the work piece W as it is delivered inwardlyto the chuck housing over the guide 20.

The described embodiment of the invention is shown in application to awork piece W, the bore of which is splined.y There is no assurance thatthe splined bore is round since it cornes to thechuck after breaching'and hardening, However, preliminary to chucking,both faces of the workpieee'are ground llatand parallel. This vproduces a knife edge at thebore. rl`he described 'embodiment of the invention is so Iversatile thatit can be applied to precision chuck such a part for :grinding its.outside contour to a very close tolerance.

' `In vthe function aof the described apparatus to receive a workpiecethe rod S and disc 38 are forward =as -in Fig. 3 of the drawings. Inthis lposition the -hook -extremities of the fingers 35 are cammedwithin 'the :guide 24D, the disc 38 is forwardly out of engagement withcam surfaces 5S of the vfingers and the sleeve 33 is displaced forwardlyrelative shoulder 34. This permits the' internally bored work piecefW'tobe automatically delivered over the guide 20 and inwardly to thediaphragm .16. The inner face of the work piece may be limited by therest buttons 26 andthe knife edge ofthe bore at itsinner face is quicklyand accurately centralized by the tapered kprojection 17 of thediaphragm. VThe movement ofthe work piece inwardly to the diaphragm,causes it to engage the shedder pin elements 54 of the shedder 43 tobias the shedder inwardly towards the rear `of housing 1 against thebias of the springs 50. On movement of the draw bar rearwardly of body1, disc 38 `engages cam surfaces 5S ofngers 35 applying an outward biasof the lingers about pivots '56 and 1a rearward bias `of thefsleeve -33through the fingers. This effects an alignment of hook extremities 36with guide slots 37, the disc camming the hooks outwardly of the guidethrough slots37 to engage the hooks 36 over the outer face of the workpiece at itsiinner,periphery in lines constituting chords of acircle..At this point rod 5 'zis retracted in the rear end of guide 2li, andthe 'engaging .pressure of disc `38 imposes abias of sleeve 33 toshoulder 34 that'compresses and energiz'eszsprings39 therebetween. Thework piece is thus biased to a bore edge mounting. Also, as the rod 5moves rearwardly it cams ythe latch 40 clockwise andcauses its hookextremity 47 to engage in the notch 48A of the shedder under the bias ofstud 42 to hold the shedder in its rearward position.

It is noted that the taper angle of thediaphragmprojection 17 locatesthe workpiece centrally by means of the bore edge and 4prevents agrinding wheel from moving the piece out 'of this centralposition.

The chucking of the work.piecedisposeszit'ima rela- ".tively free state,completely relaxed, 'and :free `of any .holding distortion. ThisV'enables a 'peripheral :grinding Y:of 'the work :piece in precisionfashion since :the .twork piece, though relaxed, is contained againstdisplacement and the operation may be elected without inducement ofworking stresses therein due to its relaxed mounting.

For automatic ejection of the work piece, the rod need merely be movedforward to cause the latch arm 46 projecting into the notch 41 in therod 5 to be cammed counterclockwise to disengage the latch from theshedder against the bias of the radially engaged stud 42. As the sheddermoves forward under the influence of the biasing springs 50 which werecompressed on chucking, the shedder pins start to move outwardly of thediaphragm. Also, as the rod 5 moves forward, the disc 38 relieves itspressure on lingers 35. The springs 39, being thus relieved, trigger thesleeve 33 and connected fingers forwardly to start the camming of thehook extremities 36 within guide 20. Due to the enlargement of rod 5relative extension 32, a shoulder provided at the extremity of rod 5engages the adjacent end face o'f sleeve 33 as it moves forward to causethe latch elements to be completely cammed within guide 20 in a mannerbelieved obvious. Under the influence of springs 50, the shedder pins S4engage and eject the work piece W from the guide 20.

As may be readily seen, the operation ofthe internal tainment issubstantially stress free and very effective to,v maintain a work piecefor precision machining of its outer periphery.

From the above description it will be apparent that there is thusprovided a device of the character described possessingthe particularfeatures of advantage before enumerated as desirable, butV whichobviously is susceptible of modificationin its form, proportions,`detail construction and arrangement of parts without departing vfromthe principle Ainvolved or sacrificing any. of its advantages.

While in order to comply with the statute the invention has beendescribed in language more or less specific as to structural features,it is to be understood that the invention is not limited to the specificfeatures shown, but that the means and construction herein disclosedcomprise but one of several modes of putting the invention into effect,and the invention is therefore claimed in any of its forms ormodifications within the legitimate and valid scope of the appendedclaims.

Having thus described our invention, we claim:

l. A chuck including a chuck housing, means projecting from one face ofsaid housing for guiding a work piece thereto and resiliently mountedmeans projecting from said one face of said housing for automaticallypositioning the work piece by engagement of a single edge thereof.

2. A chuck including a housing, a resilient diaphragm mounted to saidhousing having means connected for edge mounting a work piece theretoand means mounted to said housing for clamping the workpiece to saiddiaphragm in its edge mounted position.

3. A chuck including, a housing, a resilient diaphragm over one facethereof, guide means projecting from said housing for guiding a workpiece to abut said diaphragm, circumferentially extended slots in saidguide means and means within said guide means automatically projectablethrough said slots to bridge the outermost surface of the work piece andlock it to said diaphragm.

4. An internal chuck including, a housing having a resilient annularbore edge centering means for freely positioning an internally boredwork piece thereto and Vcircularly arranged clamp means mounted to saidhousing for externally engaging and resiliently balancing, the workpiece to said bore edge centering means.

5. A chuck including, an axially apertured housing, a draw bar elementbearing in said housing and Vextending through the aperture therein,meansv for preventing rotation of said element relative said housing,said housing having a chucking face to one end of said element, aresilient centering device at said chucking face having a smoothlycontoured surface for edge mounting a work piece toprevent planarshifting thereof and means connected -to said draw bar element incircumferentially spaced positions and operative to engage the workpiece in biased relation to said contoured surface.

6. An internal chuck including, a housing, a draw bar element extendingaxially through and bearing in said housing, a work guide element of atubular nature projecting from the work receivingrface of said housingabout the projecting end of said draw bar element, a relativelyexpanded-portion at the projecting end ofY saidbar element, a sleeve onsaid projecting end of said bar element.

within said expanded 'portion having latch elements pivoted theretocircumferentially thereof and adapted for automatic radial projectionrelative said guide element by said expanded portion of said bar elementfor locking a work piece to the work receiving face-of said housing.

7. A chuck comprising, a chuck housing having a recessed face, adiaphragm `over said recessed face. having bore edge positioning meanscentrally thereof for positioning an internally bored work piece to saidhousing, shedder means in 'said housing having shedder elements adaptedto project through said diaphragm, latch means -pivoted in said housingfor latching said shedder means :therein on chucking. al work piece tosaid-'bore edge positioning means and means for pivoting said vlatchmeans to release said shedder'means for projection of said shedderelements to automatically eject the work piece from a chucked condition.

8. Anvinternal chuck comprisinga chuckhousing, a diaphrgam mounted overone face of the chuck housing, said housing having an axial aperture,said diaphragm havingy an aperture axially aligned with said aperture inYVsaid housing, the portion of said diaphragm about the aperture thereinbeing tapered, a draw bar operatedV element in said housing projectablethrough said apertures, the projectable end of said 4draw bar havingmeans thereon including latch elements pivotally connected thereto,means for guiding a work piece to said diaphragm for edge mounting toits tapered portion, said latch elements on said draw bar element beingprojectable to engage the Work piece in its edge mounted condition tosaid diaphragm by movement of said bar element inwardly relative saidhousing.

9. A draw bar operated chuck including, a chuck housing, said housinghaving an aperture, a draw bar element reciprocably mounted relativesaid housing and within the aperture therein, the outer end of said drawbar element projecting from the chucking face of said housing, agenerally tubular guide element projecting from the chucking face of thesaid housing affording a bearing for said draw bar element and meansmounted to said draw bar element within said tubular guide element forprojection from said guide element for locking a work piece to saidchuck housing on delivery over said guide element and means mounted insaid chuck housingrand cooperatively engaged in a notch in said draw barelement controlling the movement of said draw bar elementrelative saidhousing.

l0. An internal chuck comprising, a housing centrallyV 7 said sleeve,said vretainer .means kineluding means for biasing said latch elementstoproject radially of said guide element whereby .in one position -of`said-.draw bar element, a work piece lmay -be received over `said guideelement to said housing and in a second Iposition ofsaid -draw -fbarelement said latch elements .will automatically engage the work piece tosaid chuck housing.

11. An linternal chuck including, a chuck housing, resilient rmeans forbore edge mounting of a Work piece having an Vinternal bore to one face.of `said housing and means mounted to said housing Vand operable forcontaining `the work piece in a resiliently mounted .condition to `saidA,bore edge mounting means.

12. A chuck including, a ychuck housing, Vmeans lprojectingfrom one facekof said ,housing =forguiding a Work4 ,piece thereto, resilient meansprojecting from said one face 'of said housing .for automaticallypositioning the wol-.k piece by engagement of `asingle edge thereof, arod reciprocably mounted -within said housing for projection throughsaid Work guide means on said rod including circular-ly spaced elementsoperative to contain a work piece delivered Vover said guide to saidedge positioning means. .Y

13. A .chuck including, a vchuck housing,frneans pro- ,.jecting .fromone face-=of said housing for guiding a Work piece thereto, vmeansrprojecting from said one face of said housing fior automaticallypositioning `the workpiece by Vengagement of a single edge thereof, arodreciprocably mountedl Within said housing for projection thronghisaidWork guide, means on vsaidrod operative lto contain a workpiecedelivered over said ,guide .to said edge positioning means, sheddermeans in said housing :for kprojection 'to feject the work piece, meansfor .latch ing said shedder means on clutching a workpiece, said rodbeing-operable to displace said containing means clear of the workpiecevand said guide means and to release said .shedder means .for ejectionlof the workpiece.

14. A chuck including, a housing, airesilentzdiaphragm mounted to saidhousing having bore edge positioning lmeans integrally connected theretofor internally chuck-- ing a work piece, a Work guide projecting fromsaid housing and through said lbore edge positioningV means, a rodrecprocahly mounted within said housing for projection through said workguide, means on said rod Vfor automatic projection through said workguide for engaging a work piece to said bore edge 4positioning means.

15. A chuck comprising, a housinghaving Work `guide means projectingfrom one face, resiliently mounted bore edge vmounting means for,positioning a work piece to said one face concentric to said guidemeans and Circularly related .means operatively related to said 'housingkfor engaging a work .piece to said bore edge mounting means, .said`cinculai'ly related means engaging the Work piece in lines constitutingchords of a circle.

Y 1.6. A rdraw bar operated chuck including, a housing v`having a Vdrawbar element vreciprocable therein to pro- Va sleeve on `said barvelement within said guide mounting the ,projectable means, meansconfining said .sleeve `for limited movement on said bar element,biasing means Yintermediatevsaid housing and sleeve Vlimiting the inwardmovement .of said :sleeve relative the housing, said projectable meansvincluding latch elements pivoted-to said sleeve, one of said confiningmeans being `operative on .retraction .of said bar elementto cam saidlatch elements'throughr said slots.

References Cited in the lle of this .patent UMTED :STATES PATENTS957,201 Gail May 10, 1910 1,491,332 Brown -Y Apr. 22, 1924 1,652,857Greve Dec'. 13, 41927' 2,050,828 Buell Aug. 11, 1936 2,473,380 Ljunggrenet al. June 14, 1949 '#2,820,641 Garrison Jan. 21, "1958 7. gevel, W,

u, of $1123"

